Dampening water circulation system for offset press

Abstract: A dampening water circulation system achieves further lightweighting, easy maintenance and decreases a heat energy influencing the temperature of the dampening water. There are provide a dampening water supply pipe 50 and the dampening water pool bar 60 along the water fountain roller 20. The dampening water pool bar and the water fountain roller are arranged to maintain an aperture G of several mm to thereby form the water pool portion 70 between two members. The fed water can be kept in the dampening water pool portion to be applied on the water fountain roller. The dampening water pool portion is made small in size to minimize a time for the dampening water from the supply pipe 50 to the water fountain roller whereat the supplied water does not influenced by any foreign element, which can minimize the return water amount and is effective to decrease the cooling capacity for the used dampening water.

Description: BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention is broadly concerned with a dampening water circulation system used in an offset press and intended particularly to be used to a dampening water circulation system which minimizes foreign elements for the dampening water and forms uniformed water screen on form plates preferably with small water. 2. DESCRIPTION OF THE RELATED ART There are some known conventional dampening water circulation systems for the general offset press, for examples, a system wherein a ductor is adapted to intermittently contact with a water fountain roller constantly dipped in water stored in a water fountain, a system wherein a damping roller is constantly rotatably contacted with the water fountain roller, a system wherein the dampening water is fed to the damping roller by rotatably contacting a rotary brush with the water fountain roller in a state there is a gap of rotational speeds between them, and a system wherein the dampening water is sprayed over the water fountain roller. One of the conventional dampening water circulation systems will be explained in detail with reference to Fig. 21. The dampening water circulation system is essentially consisting of a dampening roller apparatus 2 to transmit the dampening water to form plates 1 of an offset press (hereinafter referred to as "press") and a dampening water circulating device 3 to control the dampening water fed to the dampening roller apparatus 2. The dampening roller apparatus 2 has a water fountain roller 20 finished thereon with chromium coating to have hydrophilic nature, a rubber roller 22 and a chromium roller 24 in a contacting state to each other in this order. The chromium roller 24 is arranged to contact with a rubber damping roller 26 whereat these serial rollers are relatively rotated to transmit the dampening water to the form plate 1. The dampening water circulating device 3 is provided to store therein a predetermined amount of dampening water constantly for the water fountain roller and further control amount, temperature and quality of the dampening water returned from a water fountain 30. Such dampening water circulation system has already taught in the Japanese Utility Model Application Publication No. Hei 4-43321. Fig. 22 is a schematical view depicting a spray type, wherein a spray nozzle 40 is disposed to oppose to a chromium roller 24 contacting with the dampening roller 26 to thereby spray the dampening water fed from a dampening water supply 4 by means of a spray nozzle 40. As has been mentioned above, in such conventional system, the water fountain roller is constantly soaked in the dampening water stored enough in the water fountain to transmit the dampening water to the following rollers. The surplus dampening water in the water fountain may cause a clogging state of a pipe extending from the water fountain because of ink and link adhered to the water fountain roller. It is therefore required for the dampening water circulating device to improve its function to remove such stains from the dampening water and cool down. In the spray system without the water fountain and the water fountain roller, it is difficult to apply the dampening water on the roller with a microscopic order and the maintenance for preventing clogging is a time-consuming job or costly. It is an object of the present invention to provide a dampening water circulation system which achieves further lightweighting and reduced cost and to complete its maintenance easily. Another object is to provide a dampening water circulation system in which an arrangement of the dampening rollers are easily modified to thereby minimize the space for their installation. A further object of the present invention is to prevent heating and clogging of the ink residues in the dampening water to be fed to the dampening roller. Summary of the invention In order to obtain the above objects, the present invention according to a first embodiment is conceived to provide a dampening water supply system for an offset press, wherein a dampening water is transmitted to a form plate via a dampening roller system comprising a fountain roller and several transmitting rollers including a dampening roller; wherein a dampening water pool means is arranged parallel to one of the rollers of the dampening roller system, comprising an elongated body extending parallel to the one roller in close relationship to the surface thereof to form a water pool portion keeping therein the dampening water fed from a dampening water supply member; and wherein a return dampening water receiving member is provided to collect therein the dampening water which is not transmitted to the transmitting rollers, characterized in that the water supply member comprises a dampening water supply pipe extending along the fountain roller or a roller adjacent to said fountain roller and having water supply openings distributed along said supply pipe and directed to the respective roller surface; and in that the elongated body comprises at least one bar to form a water pool portion between the outer surface of said bar and the fountain roller or a roller adjacent disposed upstream thereof, the water pool portion being made minimum in size to keep the necessary amount for continuous dampening of the form plate. In contrast to the known solutions, in accordance with the present invention a water pool portion of a minimum size is provided on the water fountain roller (or an adjacent roller), so that the dampening water is constantly renewed without heat and ink residues being able to pass into the water pool portion. The bar forming the elongated body constitutes a very simple and cheap structural element to achieve a minimum size water pool portion. According to another embodiment of the present invention the dampening water supply system is characterized in that the dampening water supply member comprises a dampening water supply pipe or channel extending along the fountain roller or a roller adjacent disposed upstream thereof and having water supply openings distributed along said supply pipe or channel; and in that the dampening water supply pipe or channel at the same time serves as said elongated body to form a water pool portion between the outer surface of said pipe or channel and the fountain roller or said roller adjacent thereto, wherein the water supply openings are directed to said water pool portion, the water pool portion being made minimum in size to keep the necessary amount for continuous dampening of the form plate. Those embodiments are particularly desirable from the structural point of view and, because of the small amount of space they occupy, are particularly suitable for solving the object of the invention. According to still another embodiment of the present invention the dampening water supply system is characterized in that the dampening water supply member comprises a dampening water supply pipe extending along the fountain roller or a roller adjacent disposed upstream thereof and having water supply openings distributed along said supply pipe; that the dampening water supply pipe is integrally attached to a lead plate extending along said fountain roller or said roller adjacent thereto from below said supply pipe close to the surface of the fountain roller or said roller adjacent thereto, wherein the water supply openings are directed to said lead plate, wherein the water pool portion is formed between the forward end portion of said lead plate and said fountain roller or said roller adjacent thereto, to minimize amount of dampening water uniformly applied on said fountain roller or said roller adjacent thereto, and a relief hole is provided in said lead plate to allow overflow water to pass through. The supply pipe and the lead plate form an integral structural element which, at reduced cost and space for their installation can easily be assembled. The relief hole delimits the amount of dampening water stored between the lead plate and the respective roller. EP-A-0 371 386 discloses a dampening water supply system with a kind of water pool formed between a water supplier and the circumferential surface of the fountain roller. The water supplier however in terms of its receiving volume corresponds to a normal dampening water pan. DE-A-2 203 046 and CH-A-383 413 disclose a dampening water supply system having a supply means and a lead plate. The known systems differ in structural terms from the system recited for instance in claim 11, that is to say the lead plate and the water supply pipes are not combined to form an integrated component. The following elements are also characteristic in the present invention. (1) A plurality of dampening water pool bar around the water fountain roller. (2) The rotatable dampening water pool bar. (3) The return dampening water receiving member has a convergent taper inside thereof, a gathered point of the convergent taper being opened. The invention in accordance with claim 3 is characterized to further have a dampening water feed amount control assembly to regulate feeding amount of the dampening water fed from said dampening water supply member in accordance with required quantity of water for the form plate. The following elements are also characteristic in the above mentioned invention. (1) The dampening water feed amount control assembly is adapted to have a dampening water gain function to promptly supply an additional dampening water to keep a standard amount of the dampening water in the water pool portion. (2) A feeding amount control of the dampening water by means of a sensor detecting an amount at the water pool portion or of the return dampening water. (3) A feeding amount control of the dampening water by means of a sensor detecting a printing speed. The invention cited in claim 9 is a dampening water circulation system for an offset press wherein a dampening water fed through a dampening water supply line is transmitted on a form plate via a dampening roller consisting of a water fountain roller and plural ductors arranged serially, the dampening water circulation system, has: a dampening water supply member connected with the dampening water supply line and oppositely aligned with an axis of one of the dampening roller to keep the dampening water flown out therefrom; and a return dampening water receiving member to collect therein the dampening water which does not transmitted from the water fountain roller to the ductor. The invention cited in claim 9 is a dampening water circulation system for an offset press wherein a dampening water fed through a dampening water supply line is transmitted on a form plate via a dampening roller consisting of a water fountain roller and plural ductors arranged serially, the dampening water circulation system, has: a dampening water supply member connected with the dampening water supply line and oppositely aligned with an axis of one of the dampening roller to pour the dampening water therefrom; a leading or lead plate arranged parallel to the dampening roller to guide the dampening water toward the water fountain roller or the roller adjacent to the water fountain roller; and a return dampening water receiving member to collect therein the dampening water which is not transmitted from the water fountain roller to the ductor. The invention in accordance with claim 11 is further characterized by the following limitations. (1) The lead plate made of an elastic materials, the lead plate being disposed such that a forward end thereof is kept contact with the water fountain roller or the roller adjacent to the water fountain roller. (2) The lead plate shaped such that a water pool portion is formed between the water fountain roller or the roller adjacent to the water fountain roller. (3) The lead plate formed to include a water pool portion near the water fountain roller or the roller adjacent to the water fountain roller, so that the dampening water flown over the water pool portion is applied to the water fountain roller or the roller adjacent to the water fountain roller. (4) The lead plate and the return dampening water receiving member are integrally provided. In accordance with the invention in claim 1, the dampening water fed from the dampening water supply member is kept in combination with one or more dampening water pool bars and the roller at the water pool portion from which the water fountain roller receives the necessary water. The not-transmitted water can be collected by the return dampening water receiving member and then forwarded to the dampening water regulation device via the return pipe. The water pool portion is made minimum in size to keep necessary amount of water, so that the dampening water fed out from the dampening water supply member can reach to the water fountain roller in a short period of time, which may not bring the fed water into unfavorable state because of any foreign element, so that there is no necessary to improve a cooling capacity. In accordance with the invention in claim 3, the feed amount of the dampening water by the dampening water supply member is controlled based on the amount of water in the water pool portion, the returned quantity of the dampening water or the printing speed, which is effective to save unnecessary dampening water. In accordance with the invention in claim 9, its water pool portion is formed between the dampening water supply member and the water fountain roller, so that the number of parts can be small to obtain the same objects and operation as mentioned before. In accordance with the invention in claim 11, the same objects and operation can be obtained by spreading the dampening water fed from the dampening water supply member on the lead plate while flowing down and then supplying directly on the water fountain roller or by feeding to the water fountain roller via the water pool portion provided at a forward end portion on the lead plate or between the lead plate and the water fountain roller. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagrammatic view depicting the appearance of the overall composition of a dampening water circulation system in accordance with the present invention; Fig. 2 is a perspective view depicting a main section in the dampening water circulation system; Fig. 3 is an enlarged view depicting a water pool portion; Fig. 4 is a view depicting an example of a drip pan as a return dampening water receiving member; Fig. 5 is a view depicting a system for automatically regulating supply amount of the dampening water; Fig. 6 is a perspective view depicting an embodiment to detect an overflow state at a water pool portion; Fig. 7 is a schematical view depicting the water pool portions formed by plural dampening water pool bars; Figs. 8 is a schematical view depicting the water pool portion formed by a rotatable dampening water pool bar; Fig. 9 is a diagrammatic view depicting the water pool portion made on a roller adjacent to the water fountain roller; Fig. 10 is a schematical view depicting the water pool portion formed by a dampening water supply pipe which have water supply holes; Fig. 11 is a schematical view depicting a water supply head attached on the dampening water supply pipe; Fig. 12 is a schematical view depicting a water pool portion made by a drainpipe as the dampening water supply member; Fig. 13 is a partial perspective view of Fig. 12; Fig. 14 is a diagrammatic view depicting a dampening water circulation system using a lead plate; Fig. 15 is a top view of Fig. 14 depicting an arrangement of a lead plate, a water supply pipe and the water fountain roller; Fig. 16 is a schematical view depicting the water pool portion formed by an elastic lead plate; Fig. 17 is a schematical view depicting the water pool portion formed by a lead plate; Fig. 18 is a schematical view depicting a lead plate in which the water pool portion is formed; Fig. 19 is a top view of Fig. 18 depicting an arrangement of a lead plate, a water supply pipe and the water fountain roller; Fig. 20 is a schematical view depicting a lead plate having a relief hole therein to allow overflow water pass through; Fig. 21 is a diagrammatic view depicting a conventional dampening water circulation system in a general offset press; and Fig. 22 is a diagrammatic view depicting a spray-type conventional dampening water circulation system in a general offset press. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) The preferred embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is a diagrammatic view showing a dampening water circulation system in accordance with the present invention. Incidentally, in the description of the following embodiments, the same reference numerals will be used to designate the same or similar components as those in the conventional system shown in Figs. 21 - 22, so that the description will be omitted or simplified. In the following descriptions, a water fountain roller should be understood to rake enough water on form plates from a pounded water. Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words "up", "down", "right" and "left" will designate directions in the drawings to which reference is made. The words "in" and "out" will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Such terminology will include derivatives and words of similar import. As can be seen from Figs. 1 and 2, there is provided a dampening water supply pipe 50 as a dampening water supply member along an central axis of the water fountain roller 20. The dampening water supply pipe 50 is adapted to pour dampening water over the water fountain roller 20 and the poured water can be stored by means of a dampening water pool bar 60 which is supported on a pair of brackets 61 securely attached to side frames of the press in a state parallel to the roller 20. The dampening water pool bar 60 has a length to slightly pass through the both brackets 61 and is provided at least one end with a tension control means to be stringed between the brackets 61. The stated purpose of the dampening water pool bar 60 is to form a water pool portion 70 along the water fountain roller 20 with an aperture G as shown in Fig. 3. Incidentally, the aperture G should be understood as to be changed depending upon a rotational direction of the water fountain roller 20, but in a case that the roller 20 rotates upwardly it is recommended to be kept by about 0.3 mm. The water fountain roller 20 is associated with a drip pan 52 thereunder to receive a surplus dampening water which was not transferred to a rubber roller 22 (see, Fig. 1) but dropped therefrom. It is an object for the drip pan 52 to simply gather the dropped dampening water and then return it to a dampening water regulation device 54 in which the water is reprocessed via a return pipe 53. The drip pan 52 has, as shown in Fig. 4, a semi-cylindrical configuration of which inner surface is formed to have a convergent taper 52a. The gathered point of the convergent taper 52a is opened to be connected with a drain 52b adapted to be connected with the return pipe 53. As can be seen from Fig. 2, the dampening water supply pipe 50 is adapted to feed out certain amount of dampening water uniformly over the water fountain roller 20 from plural water supply holes 51 of which shape, numbers and arrangement can be selected considering necessary amount of dampening water poured over the roller 20. The water supply hole 51 can consists of a simple hole or a slit, otherwise a spray head or a water supply head provided in a peripheral wall of the dampening water supply pipe 50. It should not be limitedly understood that the dampening water should be fed into the dampening water supply pipe 50 via a dampening water supply line 55 from one end or the left side in Fig 2, but it can be done at both ends or an intermediate portion of the pipe 50. Furthermore, the number of the dampening water supply line 55 can be a single one or plural ones. The dampening water regulation device 54 is adapted to fulfill its function to regulate and condition water to be used as the dampening water and to filter the returned dampening water. Now referring to Fig. 5, there is shown a dampening water feed amount control assembly comprises a pump 56 to feed into a dampening water supply line 55 extending therefrom the dampening water preliminarily regulated and conditioned in the dampening water regulation device 54, a flow regulating valve 57 on the way of the dampening water supply line 55, and a controller 58 to control the pump 56 and the flow regulating valve 57, so that a preferable amount of dampening water is automatically regulated in accordance with a physical quantity indicating a relationship between necessary amount of water and actually fed amount of water. In order to obtain one physical quantity, there is provided a water amount sensor 59 on the way of the return pipe 53 to detect an amount of water returned to the dampening water regulation device 54. The sensed physical quantity can be utilized to control automatically a running state of the pump 56 or an opening degree of the flow regulating valve 57. The physical quantity may be of a signal issued from a water amount sensor 59a disposed at the water pool portion 70 or from a rotational frequency sensor 59b at a plate cylinder or the form plate 1 to detect printing speed. The controller 58 further has a dampening water gain function to responsibly supply an additional dampening water into the water pool portion 70 at the beginning of running or in an irregularly and temporarily happen state of little water in the water pool portion 70 to thereby conduct fine printing. Such responsible supply of an additional dampening water may begin upon a start signal of running, so that a running state of the pump 56 or an opening degree of the flow regulating valve 57 is preferably controlled to supply dampening water additionally in a short period of time. The responsible supply of an additional dampening water also takes place through running state, when an overflow sensor 59c detects no overflow of the dampening water from the water pool portion 70 or when the water amount sensor 59 detects that return water amount from the drip pan 52 does not reach a predetermined value, so that a running state of the pump 56 or an opening degree of the flow regulating valve 57 is preferably controlled to supply dampening water additionally to thereby overcome a water shortage state. Referring to Fig. 6, there is depicted how the overflow sensor 59c detects an overflow state of the water pool portion. As can be seen from the drawing, the dampening water pool bar 60 is characterized to have at least one overflow recess 60a to constantly allow an overflow of the dampening water from the water pool portion 70. A proximity detector such as the overflow sensor 59c is arranged to oppose to the overflow recess 60a. It should be understood that only when the water pool portion 70 stores therein enough water, the overflow of the dampening water is constantly taken place via the overflow recess 60a. Accordingly, when the overflow sensor 59c notes no overflow state, it sends a corresponding signal to the controller 58 to supply the additional supply of dampening water into the water pool portion 70. It should not be limitedly understood that the additional supply of the dampening water is conducted automatically but it can be controlled manually or done by another method without any controller. Particularly, if a metering pump is utilized without any controller, the additional dampening water is supplied limitedly when the printing speed reaches maximum or if such additional supply is required to be carried out manually, it is enough for a person in charge to regulate the opening degree of the flow regulating valve. As has been explained above, the supply amount of the dampening water has been considered to be controlled by the opening degree of the flow regulating valve 57 disposed intermediately on the dampening water supply line 55, but it can be replaced with a general solenoid valve controlled by a pulse signal. Now referring to Fig. 7, the dampening water pool bar 60 may consist of several ones (two bars in the drawing) around circumference of the water fountain roller 20. Fig. 8 depicts a state that the bar 60 is adapted to rotate in relation or no relation to the water fountain roller 20 rotating. Incidentally, the rotational direction of the dampening water pool bars 60 is independent from that of the water fountain roller 20. The aperture between the bar 60 and the water fountain roller 20 in Fig. 8 is recommended to be at a range of 0 - 0.15 mm when respective rotational directions are proper or 0.1 - 0.3 mm when those are different from one another. The dampening water supply pipe 50 may be disposed near a roller 20a adjacent to the water fountain roller 20 as shown in Fig. 9. It should be naturally understood that if the aperture G between the water fountain roller 20 and the bar 60 is properly adjusted as has been explained above, the water fountain roller and other rollers rotate in an opposite direction. A brief explanation of the operation will be given for convenience. First of all, necessary amount of dampening water for fine printing is determined and then poured to the water pool portion which serves dampening water to the surface of the water fountain roller entirely. A surplus dampening water which is not transmitted from the water fountain roller to the dampening roller is gathered in the drip pan 52 and then returned to the dampening water regulation device 54. Referring to Figs. 10 and 11, they depict other embodiments of the water pool portion 70. In these embodiments, the dampening water supply pipe 50 is served as the dampening water supply member so that the water pool portion 70 is formed between them. The dampening water supply pipe 50 and the water fountain roller 20 are arranged such that an aperture G between them is generally given by 0.3 mm. It should be understood for the water supply holes 51 that if they are enough to provide predetermined amount of the dampening water to the water pool portion 70, the respective configuration thereof are not necessary to be limited. For example, as shown in Fig. 10 each of the holes 51 may have a hole or slit configuration made in the peripheral wall of the dampening water supply pipe 50 or, as shown in Fig. 11 a water supply head attached on the pipe 50 to serve the water from an upper portion to the water pool portion 70. Incidentally, the outer configuration of the dampening water supply member is not limited to a cylindrical one but can be other ones. Fig. 12 depicts another dampening water supply member shaped into a sectionally C-shaped drainpipe to form the water pool portion 70. The drainpipe 50A is provided as the dampening water supply member parallel to the water fountain roller 20. As can be recognized from Fig. 13, the water pool portion 70 may be formed between the water fountain roller 20 and the drainpipe 50A which has plural overflow recess 51a at every certain intervals on an upper portion of its side wall opposed to the water fountain roller 20. The dampening water is first fed in the drainpipe 50A via a not-shown dampening water supply line and poured to the water pool portion through the overflow recess 51a. Referring to Fig. 14, there is shown another embodiment which is characterized to have an additional leading or lead plate 80 parallel to the water fountain roller 20 to guide the dampening water toward the surface of the water fountain roller 20. The lead plate 80 consists of a vertical section behind the pipe 50 and a tilted section extending from lower end of the vertical section and is adjusted in vertical direction under the dampening water supply pipe 50. The dampening water supplied from the dampening water supply pipe 50 on the lead plate 80 is spread until served on the water fountain roller 20 while flowing down as shown in Fig. 15. This is convenient to minimize amount of dampening water uniformly applied on the water fountain roller 20. Fig. 16 is another embodiment of the lead plate made of an elastic materials. The lead plate 80 is generally a metal plate made of spring steel or a plastic plate, and of which forward end portion is always kept contacting with the surface of the water fountain roller 20 by harnessing a righting moment of the lead plate. Accordingly, the water pool portion 70 is formed between the lead plate and the water fountain roller. The dampening water fed from the dampening water supply pipe 50 is stored in the water pool portion 70 guided by the lead plate 80 to thereby applied on the water fountain roller. In this arrangement, the rotational direction of the water fountain roller 20 shown in the drawing is limited in the same direction as the tilted direction of the lead plate 80 not to catch the plate 80 under the roller 20. Fig. 17 depicts another embodiment of the lead plate. The shown lead plate 80 is located under the dampening water supply pipe 50 and is associated with a flap portion 81 which gradually closes to the water fountain roller 20 to form the water pool portion 70 between the flap portion and the water fountain roller. The dampening water supplied from the pipe 50 is spread on the lead plate 80 while flowing down and then stored in the water pool portion 70. It should be understood that an object and operation of this lead plate 80 are the same as previously explained lead plates. Fig. 18 also shows another embodiment of the lead plate in accordance with the present invention. The lead plate 80 is characteristically bent at its forward portion upwardly to form the water pool portion 82. The dampening water supplied from the dampening water supply pipe 50 is as shown in Fig. 19 spread on a slightly tilted surface of the lead plate 80 while flowing down, once stored in the water pool portion 82 and finally applied entirely on the water fountain roller 20. When the dampening water supply pipe 50 is securely attached on the lead plate 80, it is recommended to provide a relief hole 83 as shown in Fig. 20 near the dampening water supply pipe 50 and upper side than a vertical axis aligned with the water supply hole 51 so that unexpected overflow dampening water can be released through the hole 51 to the drip pan 52. The following effects are expected to be obtained in accordance with the present invention. (1) As the water fountain roller is isolated from the dampening water which is received in the drip pan and thereafter will be returned to the dampening water regulation device, it does not cause an increase of temperature of the return dampening water because of heat generated in the press. Accordingly, it will be no longer necessary to have large cooling capacity for the return water. (2) The minimum drip pan in size is preferable in view of preventing heat leakage and inclusion of ink and link. As the dampening water is adapted to be supplied as the spray method, the present invention can be applied to a dampening water supply member like a dampening water supply nozzle which is not required to apply the water to the roller in a strict manner. (3) The minimum drip pan in size is also effective to shade the dampening water stored therein from an atmosphere heat since the water does not stay long therein, so that the dampening water regulation device is not necessary to have much capacity, that is made small in size, to cool the return dampening water. As has been mentioned above, in accordance with the present invention, it is enough to supply small quantity of dampening water toward form plates for fine printing, so that the dampening water regulation device is not required to have large capacity to cool and filter the dampening water. Furthermore, a maintenance for the dampening water supply member and other devices can be simplified. Accordingly, further lightweighting and reduced cost will be achieved.

Claims: A dampening water supply system for an offset press, wherein a dampening water is transmitted to a form plate (1) via a dampening roller system comprising a fountain roller (20) and several transmitting rollers (22 to 26) including a dampening roller (26) ; wherein a dampening water pool means (60, 70) is arranged parallel to one of the rollers of the dampening roller system, comprising an elongated body extending parallel to the one roller (20) in close relationship to the surface thereof to form a water pool portion (70) keeping therein the dampening water fed from a dampening water supply member (50); and wherein a return dampening water receiving member (52) is provided to collect therein the dampening water which is not transmitted to the transmitting rollers (22 to 26), characterized in that the water supply member comprises a dampening water supply pipe (50) extending along the fountain roller (20) or a roller adjacent to said fountain roller (20) and having water supply openings (51) distributed along said supply pipe and directed to the respective roller surface; and in that the elongated body comprises at least one bar (60) to form a water pool portion (70) between the outer surface of said bar (60) and the fountain roller (20) or a roller (20a) adjacent to the fountain roller, the water pool portion being made minimum in size to keep the necessary amount for continuous dampening of the form plate. A dampening water supply system in accordance with claim 1, wherein said dampening water pool bar (60) includes tension control means to be straightly supported with a predetermined aperture (G) between the water fountain roller (20) or the roller adjacent to the water fountain roller (20) and said dampening water pool bar (60). A dampening water supply system in accordance with claims 1 or 2, further comprising a dampening water feed amount control assembly (56,57,58) to regulate feeding amount of the dampening water fed from said dampening water supply member (50) in accordance with required quantity of water for the form plate (1). A dampening water supply system in accordance with claim 3, wherein the dampening water feed amount control assembly (56,57,58) is operated based on a signal issued from; (a) a water amount sensor (59) detecting an amount of dampening water collected by said return dampening water receiving member (52); (b) a water amount sensor (59a) detecting an amount of dampening water kept in the water pool portion (70) formed by said dampening water pool bar (60); or (c) a rotational frequency sensor (59b) detecting number of revolution of a plate cylinder on which the form plate is attached or of the fountain roller (20), so that the quantity of water required for fine printing is regulated. A dampening water supply system in accordance with claims 3 or 4, wherein said dampening water pool bar (60) is provided with at least one recess (60a) to guide overflow dampening water from the water pool portion (70), and wherein the dampening water feed amount control assembly (56,57,58) is adapted to have a dampening water gain function regulating an additional dampening water amount fed from said dampening water supply member (50) in accordance with a detection signal sent from an overflow sensor (59c) detecting an overflow state at the recess (60a) or the water amount sensor (59) detecting an amount of dampening water collected by said return dampening water receiving member (52). A dampening water supply system in accordance with anyone of claims 1 to 5, wherein said return dampening water receiving member (52) has a convergent taper (52a) inside thereof, a gathered point of the convergent taper being opened. A dampening water supply system in accordance with anyone of claims 1 to 6, wherein said dampening water pool bar (60) is provided at a number of one or more with a predetermined aperture in relation to the water fountain roller, respectively. A dampening water supply system in accordance with anyone of claims 1 to 7, wherein said dampening water pool bar (60) is adapted to rotate relatively to the water fountain roller (20) or the roller (22) adjacent to the water fountain roller. A dampening water supply system according to the preamble of claim 1, characterized in that the dampening water supply member comprises a dampening water supply pipe (50) or channel (50A) extending along the fountain roller or a roller adjacent to the fountain roller and having water supply openings (51; 51a) distributed along said supply pipe or channel; and in that the dampening water supply pipe (50) or channel (50A) at the same time serves as said elongated body to form a water pool portion (70) between the outer surface of said pipe (50) or channel (50A) and the fountain roller (20) or said roller adjacent thereto, wherein the water supply openings (51; 51a) are directed to said water pool portion (70), the water pool portion being made minimum in size to keep the necessary amount for continuous dampening of the form plate. A dampening water supply system in accordance with claim 9, wherein said dampening water supply member (50A) has a sectionally C-shaped configuration. A dampening water supply system according to the preamble of claim 1, characterized in that the dampening water supply member comprises a dampening water supply pipe (50) extending along the fountain roller (20) or a roller adjacent to the fountain roller and having water supply openings (51) distributed along said supply pipe (50) ; that the dampening water supply pipe (50) is integrally attached to a lead plate (80) extending along said fountain roller (20) or said roller adjacent thereto from below said supply pipe (50) close to the surface of the fountain roller (20) or said roller adjacent thereto, wherein the water supply openings (51) are directed to said lead plate (80), wherein the water pool portion is formed between the forward end portion of said lead plate (80) and said fountain roller (20) or said roller adjacent thereto, to minimize amount of dampening water uniformly applied on said fountain roller (20) or said roller adjacent thereto, and a relief hole (83) is provided in said lead plate (80) to allow overflow water to pass through. A dampening water supply system in accordance with claim 11, wherein said lead plate (80) is made of an elastic materials, said lead plate being disposed such that a forward end thereof is kept in contact with the water fountain roller (20) or the roller adjacent to the water fountain roller. A dampening water supply system in accordance with claim 11, wherein said lead plate (80) is shaped such that a water pool portion (70) is formed between the lead plate (80) and the water fountain roller (20) or the roller adjacent to the water fountain roller.

Inventors: HARA AKIRA, ONUMA HIRAKU, HARA, AKIRA, ONUMA, HIRAKU
Applicants: BALDWIN ASIA PACIFIC CORP, BALDWIN ASIA PACIFIC CORPORATION
Application year: 1994
Main classification: B41F7
IPC codes: B41F7, B41F33